The present invention relates generally to a varnishing head.
More particularly, it relates to a varnishing head which is formed so as to move over a surface of a workpiece at a small distance from it and thereby to apply a surface coating substance onto the surface, wherein the head is provided with an application nozzle having a connection to a surface coating agent, and a suction nozzle which is open in this region and provided with a suction connection.
The present invention also relates to a varnishing device which is provided with at least two such varnishing heads.
A varnishing head of the above mentioned general type is disclosed in the German patent document DE 42 07 090 C2. It is designed so as to coat services of workpieces at a minimum distance with varnish, paint or a similar coating liquid or paste. The workpiece passes through a recess of the varnishing head along it.
With the suction connection, air passes along the workpiece surface on the application nozzle and is aspirated in the suction nozzle. The dynamic underpressure in the air stream aspirates the liquid into the application nozzle and ejects it against the workpiece surface. Due to the relative movement of the workpiece and the varnishing head, the suction nozzle moves over the freshly coated region and aspirates all excessive liquid, paint, etc. The application nozzle and the aspiration nozzle can operate in a reverse order. In a subsequent device the paint is separated and again returned to the application nozzle.
The known varnishing head operates during coating of small edges in a satisfactory manner. However, for application of a wide coating strips, in particular on a not offset surfaces, it is less suitable. Moreover, during the coating process a relatively large paint quantities are applied, which thereafter must be again aspirated and returned into the circulation.